Duelist, Guess you answered your own question!
We was at the city 4 times in 13. Twice was rain/snow. The first time in spring when most shows were not really open yet. We just bounced around-splashin in the rain, ducking in & out of stores, under awnings/bridges/ETC. Basically rain doesnt hamper us much (If we are expecting and dressed for it) ---- But yes a show is the best place to be in the rain. (for us)
Now you mentioned a pop-up shower. Well thats different. I guess in that case, you just try to take cover wherever you can.